There is a great clinical need for Point-of-Care Testing (“PoCT”) devices so that an accurate diagnosis can be made quickly, enabling appropriate treatment or response as early as possible. A rapid detection system for the diagnosis of neural injury (e.g., stroke, concussion, contusion, trauma, and aneurism) is especially important, because the treatment options for certain neural injuries such as stroke are extremely time sensitive, with maximal benefits occurring only if treatment can be initiated within the first few hours post-event.
Continuing the example of stroke, current diagnostic methodology relies on neurological expertise and advanced medical imaging techniques (e.g., Computerized Tomography/Magnetic Resonance Imaging (“CT/MRI”), which are not widely available, and are time consuming and expensive. Because of these limitations, only 4% of patients suffering from ischemic stroke receive treatment (tissue plasminogen activator) within the 3-hour effective window (Roger et al., “Heart Disease and Stroke Statistics—2011 Update: A Report From the American Heart Association,” Circulation 123(4):e18-e209 (2011)). Because of the enormity of the clinical need, much attention is focused on developing PoCT to detect pathology-specific biomarkers. Biomarkers can themselves be various substances, such as proteins, lipids, sugars, nucleic acids, or ions. Blood biomarkers for neural injury have received much attention due to the difficulties regarding timely clinical diagnosis. Currently, over 50 candidate bio-molecules including proteins, metabolites and antibodies have been identified and investigated for varied applications in diagnosis, outcome prediction, or treatment (Jickling and Sharp, “Blood Biomarkers of Ischemic Stroke,” Neurotherapeutics 8(3):349-60 (2011); Saenger and Christenson, “Stroke Biomarkers: Progress and Challenges for Diagnosis, Prognosis, Differentiation, and Treatment,” Clin. Chem. 56(1):21-33 (2010); Whiteley et al., “Blood Markers for the Prognosis of Ischemic Stroke: A Systematic Review,” Stroke 40(5):e380-9 (2009); and Hasan et al., “Towards the Identification of Blood Biomarkers for Acute Stroke in Humans: A Comprehensive Systematic Review,” Br. J. Clin. Pharmacol. (2012)). The growing list of potential biomarkers provides a useful resource to guide the development of PoCT diagnostic technologies. However, there remains a great need for a rapid detection system for the diagnosis of neural injury.
Several examples of PoCT biomarker detection technologies for the diagnosis of various diseases have recently been described. These technologies are divided into 3 major categories including chemical-, immunoassay- or nucleic acid-based detection systems with various signal readout methods such as absorbance, fluorescence, luminescence, electrochemical and colorimetric (Chin et al., “Commercialization of Microfluidic Point-of-Care Diagnostic Devices,” Lab Chip (2012)). This list includes Atolyzer® (Atonomics), Triage® (Alere), Spinit® (Biosurfit), and i-STAT® (i-STAT Corp). However, despite such PoCT systems, there remains a great need for increased sensitivity and speed in detecting biomarkers, especially neural injury biomarkers.
The present invention is directed to overcoming these and other deficiencies in the art.